Objective

To purify crude phenylacetaldehyde by distillation.

Procedure

Approximately 20ml of Phenyl acetaldehyde . was taken in a 100ml round bottom flask and distilled at about 400 mm Hg.

Results

Characterization of 35A

Discussion

Boiling point of phenylacetaldehyde expected at 400 mm Hg would be 164 C (based on the reported bp of 195C at 1 atm ), which is consistent with with observed distillation temperature at 167 C. However, the HMR of 35A showed many impurities, suggesting that distillation at a lower pressure be attempted. Also it may be necessary to discard a first fraction. When both of these steps are taken, phenylacetaldehyde is obtained pure.

Conclusion

Phenylacetaldehyde could not be purified by distilling under house vacuum (400 mm Hg)

Log

2006-10-20

1. 12:12] Approximately 20ml of Phenylacetaldehyde was taken in a 100ml round bottom flask
2. 12:40] A distillation apparatus was assembled, a hose was connected to the in house vacuum terminal (approximate pressure 400 mm Hg)
3. Phenylacetaldehyde was heated using a thermowell until it started to distill. A stable Ubergang temperature (Tu) of 167 C was recorded.
4. 13:20] A drop in the Tu marked the end of distillation. 35A was obtained as a clear oil.

exp035